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Path: sserve!manuel.anu.edu.au!munnari.oz.au!uunet!dtix!darwin.sura.net!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!caen!uwm.edu!ogicse!news.u.washington.edu!serval!hlu From: hlu@eecs.wsu.edu (H.J. Lu) Newsgroups: comp.unix.bsd Subject: Re: How to format UNIX floppies under 386BSD Message-ID: <1992Oct6.235811.29951@serval.net.wsu.edu> Date: 6 Oct 92 23:58:11 GMT References: <1992Oct5.153315.22272@ninja.zso.dec.com> <1992Oct6.145844.669@rucs2.sunlab.cs.runet.edu> <1992Oct6.173648.13606@ninja.zso.dec.com> <1asvcfINN7qu@network.ucsd.edu> Sender: news@serval.net.wsu.edu (USENET News System) Organization: School of EECS, Washington State University Lines: 28 In article <1asvcfINN7qu@network.ucsd.edu>, brian@ucsd.edu (Brian Kantor) writes: |> alan@ulka.zso.dec.com (F. Alan Jones) writes: |> >source for isa/ide lower level floppy formatting? Does there exist |> >a good reference on the subject? |> |> The manual for the floppy controller chip shows you precisely what |> you need to do to format a floppy. If you want to see example code that |> implements that flowchart, look at the IBM PC Technical Reference |> Manual in the BIOS listing, or at any of the older CP/M BIOSs. |> |> In short, what you have to do is fill up a buffer or set up a series of |> loops that will feed the image of a formatted floppy track to the floppy |> controller chip one byte at a time fast enough. DMA can help this. |> |> The usual procedure is to write a track, read it back, mark and remember |> it if it's bad, and then when you're all done writing the disk, go back |> and fill in the FAT. |> |> Note that this requires pretty heavy I/O access to the floppy controller |> chip, which isn't buffered in the PC architecture. Many systems have |> rather poor multiuser performance whilst they are formatting a floppy. |> - Brian You may try to port format stuffs from Linux. Linux can format a floppy. H.J.